EMAN410 Seminar, 3 August 2012, Physics Department, University of Otago, Dunedin, New Zealand/...
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EMAN410 Seminar, 3 August 2012, Physics Department, University of Otago, Dunedin, New Zealand/ Aotearoa Scenarios and Policies for 100% Renewable Electricity
EMAN410 Seminar, 3 August 2012, Physics Department, University
of Otago, Dunedin, New Zealand/ Aotearoa Scenarios and Policies for
100% Renewable Electricity in New Zealand and Australia Mark
Diesendorf University of New South Wales Sydney, Australia Email :
[email protected]
Slide 2
Plan of Lecture 1.Motivation, context 2.NZ 100% renewable
electricity scenario 3.Australia 100% renewable electricity
scenario 4.Policies need to drive the transition
Slide 3
Why change our Energy System? Mitigation of global climate
change resulting primarily from burning fossil fuels Gain energy
security: peak in global oil production is here; Australia peaked
in 2000 After initial investment, cap energy prices Avoid land
degradation and air & water pollution from fossil fuels Create
new local jobs in cleaner industries
Slide 4
But there are opponents
Slide 5
Context: Why focus on electricity? Biggest single source of GHG
emissions globally and in Australia, but not in New Zealand
Renewable electricity can contribute to current non- electrical
energy use: heat and urban transport Technological change could
probably be implemented faster for electricity generation than
transport or heat
Slide 6
Electricity Generation in New Zealand Electricity Generation in
New Zealand In 2011 electricity generation of 43 TWh was 23% fossil
fuelled Hydro 58%, but only 34 days of storage at peak winter
demand. Less hydro and more fossil fuels used during drought
periods.
Slide 7
Electricity Generation in New Zealand Mason, Page &
Williamson (2010), University of Canterbury Typical 10-day historic
period, fossil + existing RE, hour data
Slide 8
Simulations of 100% RE for New Zealand Mason, Page &
Williamson (2010) Method: Hydro scheduled to fill the troughs in
wind. Little geographic diversity assumed for wind RE technology
Historic annual energy generation 2011 (%) Annual energy
generation, 100% RE, max. wind, Scenario 6 (%) Data Hydro5840Daily
Wind536 hour Geothermal1324n/a, constant Biomass< 1 n/a;
peakload DemandObserved 2005-2007 hour
Slide 9
Results for New Zealand Simulations 100% RE (hydro, wind and
geothermal) is technically feasible To maintain reliability, either
additional peakload plant (biofuelled) or demand reduction is
needed. Some spillage of wind energy is inevitable during periods
of high wind and low demand NZ potential for pumped hydro storage
needs more research
Slide 10
How can Renewable Energy replace Fossil Fuels in Australia?
Energy end-use Current fossil source Comment; Renewable energy
substitute Electricity mostly coal Electricity generation -->
35% of Australias GHG emissions. 100% renewables possible before
2040. Transport mostly oil 14% of GHG emissions. Electric vehicles
for urban transport; inter-city high- speed rail; biofuels for
rural vehicles. Heat (non-electrical) mostly gas About 17% of GHG
emissions Low temperature heat from solar; some high temperature
heat from renewable electricity & possibly biofuels.
Slide 11
11 Wind, Albany, WA Solar-efficient homes, Christie Walk,
Adelaide Bioenergy, Rocky Point, Qld Sustainable Energy Future Mix
PV solar tiles, Sydney Concentrated solar Energy efficiency
Slide 12
Concentrated Solar Thermal Electricity (CST) Revival post-2004
in Spain and USA A mix of technologies at demonstration and limited
mass production stages Globally 1000 MW operating; 1000 MW under
construction; 8000 MW advanced planning; in Oz only pilot plants so
far Low-cost thermal storage in molten salts or possibly concrete,
graphite, ammonia With storage can generate 24-hour power, provided
354 MW trough system in California: Generation I is bankable
Slide 13
Gemasolar Power Tower with 15-Hour Storage in Molten Salt,
Spain Higher temperature >500C than troughs Hence more efficient
Rated power 20 MW 15 hr thermal storage Capacity factor 63%
Demonstration plant; not yet bankable
Slide 14
Australian Electricity Generation by Fuel, 2008-09 Source:
ABARE (2011) Total 261 TWh, including a little off-grid. Since
2008-09, wind 2%; solar 1%; demand growth ceased
Slide 15
Daily Demand/Load Curves: Summer & Winter Victoria,
Australia 15
Slide 16
Properties of Conventional Power Stations in Systems with
Fossil or nuclear Baseload TypeFuelsCapital cost (annualised)
Operating cost (mostly fuel) Ability to ramp Capacity factor
BaseCoal; nuclearHighLow High IntermediateGasMedium PeakHydro, gas
turbine Low for gas turbine High Low 16 Capacity factor = average
power x 100 = energy generated over period x 100 rated power energy
if operated always at rated power where average is usually
calculated over a year or over the lifetime of the station. Rated
power or capacity is maximum design power output in megawatts. Dont
confuse capacity factor with efficiency! A peak-load station may
have a capacity factor of 5-10%, but it is not necessarily
inefficient in terms of energy conversion.
Slide 17
Optimal Mix of Base- & Peak-Load Too much base-load makes
capital cost too high. Too much peak-load makes fuel cost too high
Optimal mix of base-load and peak-load gives minimum annual cost.
Installing a lot of wind shifts optimal mix towards less base-load
and more peak-load. So wind can replace coal. 17 TypeFuelsCapital
cost (annualised) Operating cost (mostly fuel) Ability to ramp
Capacity factor BaseCoal; nuclearHighLow High IntermediateGasMedium
PeakHydro, gas turbine Low for gas turbine High Low
Slide 18
Simulations of 100% RE in the Australian National Electricity
Market (NEM) Q: Could the NEM have operated in 2010 using 100%
renewable generation based on commercially available technologies?
A: Test by hourly computer simulation with real data on demand,
wind & sun. Ben Elliston, Mark Diesendorf & Iain
MacGill:
Slide 19
Data Sources QuantitySource DemandAEMO: 30 min.data aggregated
across NEM region and converted to hourly Wind (existing wind farms
in S-E)AEMO: 5-min. data converted to hourly Wind (hypothetical
wind farms in N-E)CSIRO: Air Pollution Model (TAPAM) SolarBoM:
hourly satellite data for GHI & DNI Other weatherBoM:
temperature, humidity, etc. Wind, solar and other weather data
inputted to NRELs System Advisor Model (SAM) to obtain CST and PV
outputs in selected locations
Slide 20
Simulation Method Simulation computer program written by Ben
Elliston in Python programming language. It has 3 components:
Framework supervising simulation; independent of the energy system
Integrated database of meteorology and electricity industry data
Library of simulated power generators Copper plate assumption Power
can flow unconstrained from any generation site to any load site.
Hence, demand across all NEM regions is aggregated, as is supply.
Baseline renewable energy supply mix chosen by guided trial and
error exploration
Slide 21
Baseline Renewable Energy Generation Mix in Order of Dispatch
Technology Installed capacity (GW) % of annual energy demand
(approx.) Wind, capacity factor 30%23.230 PV, flat-plate, rooftop,
capacity factor ~16% 14.610 CST with thermal storage, solar
multiple 2.5, storage 15 hr, capacity factor ~60% 15.640 Pumped
hydro (existing)2.2 Hydro without pumped storage (existing) 4.96
Gas turbines, biofuelled2414
Slide 22
Baseline NEM Simulation 2010 Summary of Results Annual
electrical energy demand (TWh)204.4NEM excludes Western Aust.
Spilled electricity (TWh)10.2 Spilled hours1606 Unserved energy
(%)0.002equals NEM reliability standard Unmet hours6All in winter
Electrical energy from gas turbines (TWh)2814% of demand Largest
supply shortfall (GW)1.334% of max. demand Maximum demand 2010
(GW)33.6
Slide 23
Supply and Demand for a Typical Week in Summer 2010 Baseline
Simulation CST behaves like a fluctuating baseload power station in
summer. Negligible GT energy used.
Slide 24
Supply and Demand for a Challenging Week in Winter 2010
Baseline Simulation CST does NOT behave like fluctuating baseload
power station in winter. Much GT energy used.
Slide 25
Effect of Increasing CST Capacity with fixed solar multiple and
storage Reduces gas turbine (GT) energy gradually and reduces unmet
hours from 6 to 2. But increases spilled hours & spilled energy
and has high cost.
Slide 26
Effect of Increasing Solar Multiple Reduces GT energy
substantially but at high cost.
Slide 27
Reducing Demand Peaks increases Reliability 5% reduction in the
6 winter demand peaks, that produce unmet hours in baseline
simulation, eliminates all unmet hours and unmet power.
Slide 28
Reducing Demand Peaks Reduces Required GT Capacity when
Reliability is Fixed By reducing GT generating capacity from 21 GW
to 15 GW, the NEM reliability standard can be met if demand during
the unmet hours is reduced by 19%. GT energy shrinks by 4%.
Slide 29
Effect of Time Delay in CST Winter Dispatch More Solar Input
goes into the Thermal Store No time delay Time delay 7h reduces GT
energy (and capacity)
Slide 30
Effect of Time Delay in CST Winter Dispatch More Solar Input
goes into the Thermal Store 5-hr dispatch delay gives quite large
reduction in GT energy use and capacity.
Slide 31
Effect of Greater Wind Diversity on Bioenergy Generation in Gas
Turbines
Slide 32
Meeting Demand without Baseload Stations Source of diagrams:
David Mills Flexible Inflexible Old concept: With baseload power
stations New concept: No baseload power stations or biofuelled gas
turbine or hydro
Slide 33
Meeting Demand without Baseload Stations RE supplied by mix of
inflexible plants (eg, wind and PV without storage) and flexible
plants (eg, CST with thermal storage, hydro with storage,
biofuelled gas turbines) Flexible plants handle the fluctuations in
power output from inflexible plants Demand management in a smart
grid can also play an important, low-cost role. The key parameter
is reliability of the whole supply-demand system, not reliability
of individual technologies
Slide 34
Future Simulation Research Required Do economics of various RE
mixes compared with various conventional mixes (gas, nuclear, coal
with CCS). (Work in progress) Remove copperplate assumption,
treating each State separately together with actual &
hypothetical transmission links. Do economics with separate states
and transmission included (Work in progress) Run multiple years,
either from empirical data or by Monte Carlo simulation
Slide 35
4 Options for Grass-Roots Social Change Ballot box necessary
but very limited influence in 2-party system Individual necessary
as an example, showing leadership, but not nearly sufficient Local
community action -- more effective than individual; can help build
state/national awareness Collective action by a social movement
huge potential, essential when democratic governments fail to
implement the will of the people
Slide 36
Collective Action to Press for Good Government Policy Policy
Science Economic s Powerful vested interests Community groups
Media
Slide 37
Policies must be appropriate to each Stage of Technology
Development R&DDemonstrationLimited mass production Large-scale
mass production Energy efficiency & conservation; hydro
Concentrated solar thermal power with thermal storage (power tower)
Off-shore wind; geothermal heat; solar space heating & cooling
On-shore wind; conventional geothermal Advanced PV; artificial
photosynthesis; advanced batteries; hydrogen fuel cells Marine; 2
nd generation biofuels; floating wind turbines; hot rock geothermal
Concentrated solar thermal power with thermal storage (troughs)
Solar hot water; solar PV; 1 st generation biofuels; solid
biomass
Slide 38
Policy Options for different Stages of Technological
Development Technology stagePolicy options (examples) R &
DGrants DemonstrationGrants; government guaranteed loans Limited
commercial deploymentFeed-in tariffs; targets with tradable
certificates; reverse auction Large-scale commercial
deploymentCarbon tax or tradable emission permits; declining
feed-in tariffs; targets with tradable certificates
Slide 39
Why a Carbon Price is Necessary Sends message to investors that
making investment in new dirty coal-fired power stations very risky
Its the only way to exert pressure for change on the whole economy.
A carbon price applied to the major greenhouse polluters flows
downstream to all economic transactions. Gives message consistent
with other policies If high enough, includes externalities
(environmental, health and social costs) in prices of fossil fuels
Raises revenue for a just transition and for infrastructure 39
Slide 40
Why a Carbon Price is Not Sufficient Market Failures $23/tonne
of CO 2 is too small to change the energy system Energy efficiency
limited by split incentives, high up-front costs, etc. Market fails
to provide infrastructure (eg, transmission lines; railways; gas
pipelines) Consumers who dont have access to alternatives must pay
the price and continue to pollute Market is short-term, based on
marginal economics; inadequate for long-term planning Market doesnt
handle risk and uncertainty well None of these market failures is a
logical argument against pricing being necessary. 40
Slide 41
Australian Govts Clean Energy Future Package Australian Govts
Clean Energy Future Package Carbon tax on major polluters for 3
years commencing 1 July 2012, followed by ETS with $15/tonne floor
price for 3 years Funding to buy out 2000 MW of brown coal power
stations Compensation to low- & medium-income earners by
tripling tax-free threshold, higher pensions, family allowances
& other benefits. $15B over 4 yrs. Clean Energy Finance
Corporation (new funding of $10B over 5 years from 2013-14) to
support investment; Coalition would terminate it Existing RE
programs placed under ARENA with independent board New long-term
greenhouse target of 80% reduction below 2000 level by 2050. But no
mechanism to achieve it. New energy efficiency assistance programs
for households, industries, small business 41
Slide 42
Principal Shortcomings of Clean Energy Future Package Big
compensation, the Energy Security Fund, to the dirtiest electricity
generators: free permits & cash worth $5.5B over 6 yrs from
2011-12. Huge assistance ($9.2B over 3 yrs) to energy-intensive
trade-exposed industries labelled as Jobs & Competitiveness
Program 50% of permits can be purchased from cheap overseas offsets
of dubious effectiveness Absence of market pull instrument, such as
feed-in tariffs, to accelerate deployment of large-scale solar
power, which has huge resource Low carbon price => gas-fired
likely to be the principal substitute for the few coal-fired power
stations that will be retired before 2020 Floor price for the ETS
is too low at $15/tonne and limited to 3 years.
Slide 43
Principal Shortcomings of the Plan ctd Excessive (non-package)
support to gassy coal-mine owners: $1.3B over 6 yrs. Better to
allow these mines to close and pay out each miner $100k. Cars, LCVs
& AFF industries excluded from carbon price, reducing revenue
and putting greater costs on electricity users. Regional structural
adjustment assistance ($200M over 7 yrs from 2012-13) apparently
limited to assistance in finding another job
Slide 44
Shortcomings of Addressing only Technology I = PAT Impact =
Population x Affluence x Technology Affluence A = Consumption $
/person where Affluence A = Consumption $ /person Technology T =
Impact/Consumption I = P x (GDP)/P x I/(GDP) or I = I, an identity
Each of the 3 factors of environmental impact is amenable to
separate policies.
Slide 45
Pressure for genuine climate action is needed on Governments by
communities, business and unions UNSW Press 2009
Slide 46
Further Reading Mason,IG, Page, SC & Williamson AG (2010) A
100% electricity generation system for New Zealand utilising hydro,
wind, geothermal and biomass resources, Energy Policy 38:
3973-3984. Elliston, B., Diesendorf, M. and MacGill, I. (2012)
Simulations of scenarios with 100% renewable electricity in the
Australian National Electricity Market, Energy Policy 45:606-613.
WBGU (2011) World in Transition: a Social Contract for
Sustainability. Berlin: WBGU (German Advisory Council on Global
Change).